pathogens Case Report Pott Disease: A Tale of Two Cases Christopher Radcliffe * and Matthew Grant Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA; [email protected] * Correspondence: [email protected] Abstract: Tuberculosis is considered one of the great masqueraders alongside syphilis and vasculitis. Pott disease is recognized as a classic manifestation of tuberculosis, yet it stands as a rare infectious syndrome in regions with low tuberculosis disease burden. To illustrate the challenges of diagnosing Pott disease in these settings, we report two cases and offer a brief overview of management recommendations for vertebral osteomyelitis caused by Mycobacterium tuberculosis. Case one concerns an 81-year-old man with a remote history of incarceration who presented with altered mental status and new pleural effusions. Case two is a 49-year-old man with well-controlled HIV who was transferred to our institution after being found to have extensive destruction of L3–L5 vertebrae and bilateral iliopsoas abscesses on outpatient imaging. These stand as illustrative examples of low and high suspicion for tuberculosis, respectively, and both cases required complex diagnostic and management decisions. Keywords: tuberculosis; osteomyelitis; Pott disease; HIV 1. Introduction Citation: Radcliffe, C.; Grant, M. Pott Disease: A Tale of Two Cases. The importance of tuberculosis cannot be overstated. Globally, millions of cases occur Pathogens 2021, 10, 1158. each year [1], and an estimated 1.7 billion people were living with latent tuberculosis https://doi.org/10.3390/ infection (LTBI) in 2014 [2]. Tuberculosis disproportionately impacts vulnerable patient pathogens10091158 populations [3], case finding can prove challenging [1], and its range of clinical syndromes may hinder the diagnosis in regions with low disease burden. Following Percivall Pott’s Academic Editors: Jianjun Sun and 18th century treatise on spinal disease [4], tuberculosis of the spine is often referred to Supriyo Ray as Pott disease. A nationwide register-based study (n = 153) on Pott disease in Denmark reported a roughly three-week time lapse (median 19.5 days) between hospital contact and Received: 17 August 2021 diagnosis, with 40% of patients requiring surgery and nearly 60% developing sequelae [5]. Accepted: 7 September 2021 To highlight the clinical challenges of Pott disease, we report two cases treated in a Published: 9 September 2021 low endemicity region. Case one concerns an 81-year-old man with a remote history of incarceration who presented with altered mental status and new pleural effusions. Case Publisher’s Note: MDPI stays neutral two is a 49-year-old man with well-controlled HIV who was transferred to our institution with regard to jurisdictional claims in after being found to have extensive destruction of L3–L5 vertebrae and bilateral iliopsoas published maps and institutional affil- abscesses on outpatient imaging. These stand as illustrative examples of low and high iations. suspicion for tuberculosis, respectively, and both cases required complex diagnostic and management decisions. We also present a brief review of management strategies for Pott disease. Copyright: © 2021 by the authors. 2. Case Presentation Licensee MDPI, Basel, Switzerland. 2.1. Case One This article is an open access article An 81-year-old man with diabetes mellitus, atrial fibrillation, and chronic lower back distributed under the terms and pain was admitted after being found unresponsive and hypoglycemic. After the return conditions of the Creative Commons of euglycemia, the patient reported decreased appetite and a recent uptick in his insulin Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ requirement. Physical exam was reportedly normal aside from mild confusion and an ir- 4.0/). regularly irregular rhythm. Laboratory studies were significant for mild hyponatremia (Na Pathogens 2021, 10, 1158. https://doi.org/10.3390/pathogens10091158 https://www.mdpi.com/journal/pathogens Pathogens 2021, 10, x FOR PEER REVIEW 2 of 7 Pathogens 2021, 10, 1158 2 of 7 requirement. Physical exam was reportedly normal aside from mild confusion and an ir- regularly irregular rhythm. Laboratory studies were significant for mild hyponatremia (Na130 mmol/L;130 mmol/L; reference reference range range 135–145 135–145 mmol/L), mmol/L), anemia anemia (11.3 g/dL; (11.3 ref.g/dL; range ref. 12–18range g/dL12–18), g/dL),and lymphopenia and lymphopenia (800/µ (800/L; ref.μL; range ref. range 1000–4000/ 1000–4000/µL). AμL). computed-tomography A computed-tomography (CT) (CT) scan scanof the of head the head without without contrast contrast was unremarkable,was unremarkable, but a but chest a chest radiograph radiograph uncovered uncovered a mod- a moderatelyerately sized, sized, right right pleural pleural effusion. effusion. Two setsTwo of se peripheralts of peripheral blood blood cultures cultures were obtained.were ob- tained.The following day, additional studies revealed elevated pro B-type natriuretic pep- tide (2337The following pg/mL; ref.day, range:additional <300 studies pg/mL), revealed sedimentation elevated ratepro (39B-type mm/hr; natriuretic ref. range: pep- tide0–20 (2337 mm/hr pg/mL;), and ref. high range: sensitivity <300 pg/mL), C-reactive sedimentation protein (hsCRP) rate (39 mm/hr; (69 mg/L; ref. range: ref. range: 0–20 mm/hr),0.1–3 mg/L and). high A CT sensitivity scan of theC-reactive chest without protein contrast(hsCRP) (69 demonstrated mg/L; ref. range: findings 0.1–3 compati- mg/L). Able CT with scan discitis of the and chest osteomyelitis without contrast at T10–T11 demon levelstrated (Figure findings1), moderate compatible to large with bilateral discitis andpleural osteomyelitis effusions withat T10–T11 associated level compressive (Figure 1), moderate atelectasis to of large the adjacentbilateral pleural lower lobes, effusions con- withsolidation associated of the compressive right middle lobe,atelectasis cardiomegaly, of the adjacent a small lower pericardial lobes, effusion, consolidation lung nodules of the rightmeasuring middle up lobe, to 1 cardiomegaly, cm, scattered calcifieda small pericardial granulomas, effusion, and mildly lung nodules enlarged measuring intrathoracic up lymph nodes. to 1 cm, scattered calcified granulomas, and mildly enlarged intrathoracic lymph nodes. Figure 1. Computed-tomography scan of chest showin showingg T10–T11 discitis and osteomyelitis. ( (AA)) Coronal Coronal view view with with red, red, interrupted circle highlighting destructive changes to vertebral bodies. (B) Sagittal view. interrupted circle highlighting destructive changes to vertebral bodies. (B) Sagittal view. A transthoracic echocardiogram showed progression of aortic stenosis, mild mitral and aortic regurgitation, and preserved ejectionejection fractionfraction (50–55%).(50–55%). Follow-up magnetic resonanceresonance imaging (MRI) with contrast confirmed confirmed discitis–osteomyelitis at T10–T11 with epidural phlegmon or or abscess causing severe central canal stenosis. Further Further history history re- re- vealed that he had been experiencing dyspnea on exertion for roughly three months.months. A right thoracentesis was was performed performed on on hospit hospitalal day day (HD) (HD) 2 2 with with a a return of 2 L of bloody pleural fluid. fluid. Pleural Pleural fluid fluid studies were consistent with an exudative effusion and demonstrated 19,000 red cells/μµLL along along with with 2857 nucleated cells/μµLL (64% (64% lymphocytes). lymphocytes). Cytology was was negative negative for for malignant malignant cells cells but but noted noted chronic chronic inflammation. inflammation. Bacterial, Bacterial, fun- gal,fungal, and and acid-fast acid-fast bacillus bacillus (AFB) (AFB) cultures cultures were were also also sent sent and and ultimately ultimately returned returned negative. negative. Routine sputum sputum culture culture on on HD3 HD3 showed showed 2+ 2+ no normalrmal flora. flora. Peripheral Peripheral blood blood cultures cultures col- lectedcollected on onadmission admission were were reported reported as negative as negative on onHD5. HD5. Given the continued concern concern for for malignancy malignancy,, a a repeat right thoracentesis was was per- per- formedformed onon HD9.HD9. PleuralPleural fluid fluid studies studies were were again again exudative exudative with with 9000 9000 red red cells/ cells/µL,μ 2575L, 2575 nu- nucleatedcleated cells/ cells/µLμ (77%L (77% lymphocytes), lymphocytes), and and negative negative adenosine adenosine deaminase deaminase (6.2 (6.2 U/L). U/L). Repeat Re- peatcytology cytology studies studies were unchanged.were unchanged. Bacterial Bacterial culture culture of pleural of fluidpleural was fluid sent was and sent returned and negative. Infectious diseases was consulted the same day, and further history revealed Pathogens 2021, 10, 1158 3 of 7 subacute cough with minimal sputum and an 18 kg weight loss in the preceding six months. The patient also reported a remote history of brief incarceration. He was transferred to a negative-pressure room given concern for active tuberculosis. Three AFB sputum cultures were collected. On HD13, QuantiFERON®-TB Gold resulted as positive (0.83 IU/mL; negative <0.35 IU/mL). A CT-guided biopsy of the left inferior T10 endplate was obtained on HD16, and pathology returned as consistent with discitis/osteomyelitis. AFB staining of the biopsy specimen was negative, and the specimen was